In various applications, an area, for example an area of a sample to be examined, needs to be scanned with a light beam. For instance, in laser scanning microscopy (LSM), where a sample is scanned with a laser beam, and light emitted by the sample in response to being irradiated with the laser beam is detected. For scanning, the laser beam is directed at one or more tiltable mirrors, also referred to as scanning mirrors. By tilting the one or more mirrors, a position of the laser beam on the sample may be adjusted. For example, in some applications a single mirror tiltable about two perpendicular axes may be used. In other implementations, two successive mirrors each being tiltable only about one axis, the axes of the two mirrors being not collinear with each other, for example perpendicular to each other, may be used.
In many applications, additionally position sensors are employed to determine a current position of the one or more movable mirrors. Various kinds of such position sensors may be used.
Movable mirrors may for example be manufactured as microelectromechanical systems (MEMS). In such microelectromechanical systems, for example the parts actuating the mirror (i.e. moving the mirror), and in some cases also the mirror itself may be formed in a semiconductor wafer, for example a silicon wafer, together with electronic components.
Conventionally, such movable mirrors are provided as a device together with analog amplifiers amplifying one or more analog signals from a position sensitive device like a four quadrant diode. The amplified analog signals are then transmitted to some target hardware for example via a suitable connection (for example with a plug-in connector). In the target hardware, the amplified analog signals provided by the movable mirror device may then be digitized and further processed, for example to determine the position of the mirror and to control the mirror accordingly.
This approach may be disadvantageous in term of calibration needed for the mirror device and regarding flexibility. For example, a certain calibration may only be valid for a certain combination of scanning device and target hardware, such that when the scanning device needs to be replaced, a recalibration becomes necessary. Furthermore, because of the calibration being necessary, it is difficult for a single conventional movable mirror device to interact with different target hardwares.